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tracing: Create seq_buf layer in trace_seq

Browse Source 
Create a seq_buf layer that trace_seq sits on. The seq_buf will not
be limited to page size. This will allow other usages of seq_buf
instead of a hard set PAGE_SIZE one that trace_seq has.

Link: http://lkml.kernel.org/r/20141104160221.864997179@goodmis.org
Link: http://lkml.kernel.org/r/20141114011412.170377300@goodmis.org

Tested-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt (Red Hat) 2014-06-25 15:54:42 -04:00 committed by Steven Rostedt
parent 16a8ef2751
commit 3a161d99c4
8 changed files with 536 additions and 124 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

81
include/linux/seq_buf.h Normal file
View File

@ -0,0 +1,81 @@
#ifndef _LINUX_SEQ_BUF_H
#define _LINUX_SEQ_BUF_H
#include <linux/fs.h>
/*
* Trace sequences are used to allow a function to call several other functions
* to create a string of data to use.
*/
/**
* seq_buf - seq buffer structure
* @buffer: pointer to the buffer
* @size: size of the buffer
* @len: the amount of data inside the buffer
* @readpos: The next position to read in the buffer.
*/
struct seq_buf {
unsigned char *buffer;
unsigned int size;
unsigned int len;
unsigned int readpos;
};
static inline void
seq_buf_init(struct seq_buf *s, unsigned char *buf, unsigned int size)
{
s->buffer = buf;
s->size = size;
s->len = 0;
s->readpos = 0;
}
/*
* seq_buf have a buffer that might overflow. When this happens
* the len and size are set to be equal.
*/
static inline bool
seq_buf_has_overflowed(struct seq_buf *s)
{
return s->len == s->size;
}
static inline void
seq_buf_set_overflow(struct seq_buf *s)
{
s->len = s->size;
}
/*
* How much buffer is left on the seq_buf?
*/
static inline unsigned int
seq_buf_buffer_left(struct seq_buf *s)
{
if (seq_buf_has_overflowed(s))
return 0;
return (s->size - 1) - s->len;
}
extern __printf(2, 3)
int seq_buf_printf(struct seq_buf *s, const char *fmt, ...);
extern __printf(2, 0)
int seq_buf_vprintf(struct seq_buf *s, const char *fmt, va_list args);
extern int
seq_buf_bprintf(struct seq_buf *s, const char *fmt, const u32 *binary);
extern int seq_buf_print_seq(struct seq_file *m, struct seq_buf *s);
extern int seq_buf_to_user(struct seq_buf *s, char __user *ubuf,
int cnt);
extern int seq_buf_puts(struct seq_buf *s, const char *str);
extern int seq_buf_putc(struct seq_buf *s, unsigned char c);
extern int seq_buf_putmem(struct seq_buf *s, const void *mem, unsigned int len);
extern int seq_buf_putmem_hex(struct seq_buf *s, const void *mem,
unsigned int len);
extern int seq_buf_path(struct seq_buf *s, const struct path *path);
extern int seq_buf_bitmask(struct seq_buf *s, const unsigned long *maskp,
int nmaskbits);
#endif /* _LINUX_SEQ_BUF_H */

12
include/linux/trace_seq.h
View File

@ -1,7 +1,7 @@
#ifndef _LINUX_TRACE_SEQ_H
#define _LINUX_TRACE_SEQ_H
#include <linux/fs.h>
#include <linux/seq_buf.h>
#include <asm/page.h>
@ -12,16 +12,14 @@
struct trace_seq {
unsigned char buffer[PAGE_SIZE];
unsigned int len;
unsigned int readpos;
struct seq_buf seq;
int full;
};
static inline void
trace_seq_init(struct trace_seq *s)
{
s->len = 0;
s->readpos = 0;
seq_buf_init(&s->seq, s->buffer, PAGE_SIZE);
s->full = 0;
}
@ -37,7 +35,7 @@ trace_seq_init(struct trace_seq *s)
static inline unsigned char *
trace_seq_buffer_ptr(struct trace_seq *s)
{
return s->buffer + s->len;
return s->buffer + s->seq.len;
}
/**
@ -49,7 +47,7 @@ trace_seq_buffer_ptr(struct trace_seq *s)
*/
static inline bool trace_seq_has_overflowed(struct trace_seq *s)
{
return s->full || s->len > PAGE_SIZE - 1;
return s->full || seq_buf_has_overflowed(&s->seq);
}
/*

1
kernel/trace/Makefile
View File

@ -29,6 +29,7 @@ obj-$(CONFIG_RING_BUFFER_BENCHMARK) += ring_buffer_benchmark.o
obj-$(CONFIG_TRACING) += trace.o
obj-$(CONFIG_TRACING) += trace_output.o
obj-$(CONFIG_TRACING) += trace_seq.o
obj-$(CONFIG_TRACING) += seq_buf.o
obj-$(CONFIG_TRACING) += trace_stat.o
obj-$(CONFIG_TRACING) += trace_printk.o
obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o

341
kernel/trace/seq_buf.c Normal file
View File

@ -0,0 +1,341 @@
/*
* seq_buf.c
*
* Copyright (C) 2014 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
*
* The seq_buf is a handy tool that allows you to pass a descriptor around
* to a buffer that other functions can write to. It is similar to the
* seq_file functionality but has some differences.
*
* To use it, the seq_buf must be initialized with seq_buf_init().
* This will set up the counters within the descriptor. You can call
* seq_buf_init() more than once to reset the seq_buf to start
* from scratch.
*/
#include <linux/uaccess.h>
#include <linux/seq_file.h>
#include <linux/seq_buf.h>
/* How much buffer is written? */
#define SEQ_BUF_USED(s) min((s)->len, (s)->size - 1)
/**
* seq_buf_print_seq - move the contents of seq_buf into a seq_file
* @m: the seq_file descriptor that is the destination
* @s: the seq_buf descriptor that is the source.
*
* Returns zero on success, non zero otherwise
*/
int seq_buf_print_seq(struct seq_file *m, struct seq_buf *s)
{
unsigned int len = SEQ_BUF_USED(s);
return seq_write(m, s->buffer, len);
}
/**
* seq_buf_vprintf - sequence printing of information.
* @s: seq_buf descriptor
* @fmt: printf format string
* @args: va_list of arguments from a printf() type function
*
* Writes a vnprintf() format into the sequencce buffer.
*
* Returns zero on success, -1 on overflow.
*/
int seq_buf_vprintf(struct seq_buf *s, const char *fmt, va_list args)
{
int len;
WARN_ON(s->size == 0);
if (s->len < s->size) {
len = vsnprintf(s->buffer + s->len, s->size - s->len, fmt, args);
if (s->len + len < s->size) {
s->len += len;
return 0;
}
}
seq_buf_set_overflow(s);
return -1;
}
/**
* seq_buf_printf - sequence printing of information
* @s: seq_buf descriptor
* @fmt: printf format string
*
* Writes a printf() format into the sequence buffer.
*
* Returns zero on success, -1 on overflow.
*/
int seq_buf_printf(struct seq_buf *s, const char *fmt, ...)
{
va_list ap;
int ret;
va_start(ap, fmt);
ret = seq_buf_vprintf(s, fmt, ap);
va_end(ap);
return ret;
}
/**
* seq_buf_bitmask - write a bitmask array in its ASCII representation
* @s: seq_buf descriptor
* @maskp: points to an array of unsigned longs that represent a bitmask
* @nmaskbits: The number of bits that are valid in @maskp
*
* Writes a ASCII representation of a bitmask string into @s.
*
* Returns zero on success, -1 on overflow.
*/
int seq_buf_bitmask(struct seq_buf *s, const unsigned long *maskp,
int nmaskbits)
{
unsigned int len = seq_buf_buffer_left(s);
int ret;
WARN_ON(s->size == 0);
/*
* The last byte of the buffer is used to determine if we
* overflowed or not.
*/
if (len > 1) {
ret = bitmap_scnprintf(s->buffer + s->len, len, maskp, nmaskbits);
if (ret < len) {
s->len += ret;
return 0;
}
}
seq_buf_set_overflow(s);
return -1;
}
/**
* seq_buf_bprintf - Write the printf string from binary arguments
* @s: seq_buf descriptor
* @fmt: The format string for the @binary arguments
* @binary: The binary arguments for @fmt.
*
* When recording in a fast path, a printf may be recorded with just
* saving the format and the arguments as they were passed to the
* function, instead of wasting cycles converting the arguments into
* ASCII characters. Instead, the arguments are saved in a 32 bit
* word array that is defined by the format string constraints.
*
* This function will take the format and the binary array and finish
* the conversion into the ASCII string within the buffer.
*
* Returns zero on success, -1 on overflow.
*/
int seq_buf_bprintf(struct seq_buf *s, const char *fmt, const u32 *binary)
{
unsigned int len = seq_buf_buffer_left(s);
int ret;
WARN_ON(s->size == 0);
if (s->len < s->size) {
ret = bstr_printf(s->buffer + s->len, len, fmt, binary);
if (s->len + ret < s->size) {
s->len += ret;
return 0;
}
}
seq_buf_set_overflow(s);
return -1;
}
/**
* seq_buf_puts - sequence printing of simple string
* @s: seq_buf descriptor
* @str: simple string to record
*
* Copy a simple string into the sequence buffer.
*
* Returns zero on success, -1 on overflow
*/
int seq_buf_puts(struct seq_buf *s, const char *str)
{
unsigned int len = strlen(str);
WARN_ON(s->size == 0);
if (s->len + len < s->size) {
memcpy(s->buffer + s->len, str, len);
s->len += len;
return 0;
}
seq_buf_set_overflow(s);
return -1;
}
/**
* seq_buf_putc - sequence printing of simple character
* @s: seq_buf descriptor
* @c: simple character to record
*
* Copy a single character into the sequence buffer.
*
* Returns zero on success, -1 on overflow
*/
int seq_buf_putc(struct seq_buf *s, unsigned char c)
{
WARN_ON(s->size == 0);
if (s->len + 1 < s->size) {
s->buffer[s->len++] = c;
return 0;
}
seq_buf_set_overflow(s);
return -1;
}
/**
* seq_buf_putmem - write raw data into the sequenc buffer
* @s: seq_buf descriptor
* @mem: The raw memory to copy into the buffer
* @len: The length of the raw memory to copy (in bytes)
*
* There may be cases where raw memory needs to be written into the
* buffer and a strcpy() would not work. Using this function allows
* for such cases.
*
* Returns zero on success, -1 on overflow
*/
int seq_buf_putmem(struct seq_buf *s, const void *mem, unsigned int len)
{
WARN_ON(s->size == 0);
if (s->len + len < s->size) {
memcpy(s->buffer + s->len, mem, len);
s->len += len;
return 0;
}
seq_buf_set_overflow(s);
return -1;
}
#define MAX_MEMHEX_BYTES 8U
#define HEX_CHARS (MAX_MEMHEX_BYTES*2 + 1)
/**
* seq_buf_putmem_hex - write raw memory into the buffer in ASCII hex
* @s: seq_buf descriptor
* @mem: The raw memory to write its hex ASCII representation of
* @len: The length of the raw memory to copy (in bytes)
*
* This is similar to seq_buf_putmem() except instead of just copying the
* raw memory into the buffer it writes its ASCII representation of it
* in hex characters.
*
* Returns zero on success, -1 on overflow
*/
int seq_buf_putmem_hex(struct seq_buf *s, const void *mem,
unsigned int len)
{
unsigned char hex[HEX_CHARS];
const unsigned char *data = mem;
unsigned int start_len;
int i, j;
WARN_ON(s->size == 0);
while (len) {
start_len = min(len, HEX_CHARS - 1);
#ifdef __BIG_ENDIAN
for (i = 0, j = 0; i < start_len; i++) {
#else
for (i = start_len-1, j = 0; i >= 0; i--) {
#endif
hex[j++] = hex_asc_hi(data[i]);
hex[j++] = hex_asc_lo(data[i]);
}
if (WARN_ON_ONCE(j == 0 || j/2 > len))
break;
/* j increments twice per loop */
len -= j / 2;
hex[j++] = ' ';
seq_buf_putmem(s, hex, j);
if (seq_buf_has_overflowed(s))
return -1;
}
return 0;
}
/**
* seq_buf_path - copy a path into the sequence buffer
* @s: seq_buf descriptor
* @path: path to write into the sequence buffer.
*
* Write a path name into the sequence buffer.
*
* Returns zero on success, -1 on overflow
*/
int seq_buf_path(struct seq_buf *s, const struct path *path)
{
unsigned int len = seq_buf_buffer_left(s);
unsigned char *p;
WARN_ON(s->size == 0);
p = d_path(path, s->buffer + s->len, len);
if (!IS_ERR(p)) {
p = mangle_path(s->buffer + s->len, p, "\n");
if (p) {
s->len = p - s->buffer;
return 0;
}
}
seq_buf_set_overflow(s);
return -1;
}
/**
* seq_buf_to_user - copy the squence buffer to user space
* @s: seq_buf descriptor
* @ubuf: The userspace memory location to copy to
* @cnt: The amount to copy
*
* Copies the sequence buffer into the userspace memory pointed to
* by @ubuf. It starts from the last read position (@s->readpos)
* and writes up to @cnt characters or till it reaches the end of
* the content in the buffer (@s->len), which ever comes first.
*
* On success, it returns a positive number of the number of bytes
* it copied.
*
* On failure it returns -EBUSY if all of the content in the
* sequence has been already read, which includes nothing in the
* sequence (@s->len == @s->readpos).
*
* Returns -EFAULT if the copy to userspace fails.
*/
int seq_buf_to_user(struct seq_buf *s, char __user *ubuf, int cnt)
{
int len;
int ret;
if (!cnt)
return 0;
if (s->len <= s->readpos)
return -EBUSY;
len = s->len - s->readpos;
if (cnt > len)
cnt = len;
ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);
if (ret == cnt)
return -EFAULT;
cnt -= ret;
s->readpos += cnt;
return cnt;
}

39
kernel/trace/trace.c
View File

@ -939,19 +939,20 @@ out:
return ret;
}
/* TODO add a seq_buf_to_buffer() */
static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
{
int len;
if (s->len <= s->readpos)
if (s->seq.len <= s->seq.readpos)
return -EBUSY;
len = s->len - s->readpos;
len = s->seq.len - s->seq.readpos;
if (cnt > len)
cnt = len;
memcpy(buf, s->buffer + s->readpos, cnt);
memcpy(buf, s->buffer + s->seq.readpos, cnt);
s->readpos += cnt;
s->seq.readpos += cnt;
return cnt;
}
@ -4315,6 +4316,8 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
goto out;
}
trace_seq_init(&iter->seq);
/*
* We make a copy of the current tracer to avoid concurrent
* changes on it while we are reading.
@ -4511,18 +4514,18 @@ waitagain:
trace_access_lock(iter->cpu_file);
while (trace_find_next_entry_inc(iter) != NULL) {
enum print_line_t ret;
int len = iter->seq.len;
int len = iter->seq.seq.len;
ret = print_trace_line(iter);
if (ret == TRACE_TYPE_PARTIAL_LINE) {
/* don't print partial lines */
iter->seq.len = len;
iter->seq.seq.len = len;
break;
}
if (ret != TRACE_TYPE_NO_CONSUME)
trace_consume(iter);
if (iter->seq.len >= cnt)
if (iter->seq.seq.len >= cnt)
break;
/*
@ -4538,7 +4541,7 @@ waitagain:
/* Now copy what we have to the user */
sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
if (iter->seq.readpos >= iter->seq.len)
if (iter->seq.seq.readpos >= iter->seq.seq.len)
trace_seq_init(&iter->seq);
/*
@ -4576,16 +4579,16 @@ tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter)
/* Seq buffer is page-sized, exactly what we need. */
for (;;) {
count = iter->seq.len;
count = iter->seq.seq.len;
ret = print_trace_line(iter);
count = iter->seq.len - count;
count = iter->seq.seq.len - count;
if (rem < count) {
rem = 0;
iter->seq.len -= count;
iter->seq.seq.len -= count;
break;
}
if (ret == TRACE_TYPE_PARTIAL_LINE) {
iter->seq.len -= count;
iter->seq.seq.len -= count;
break;
}
@ -4666,13 +4669,13 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
/* Copy the data into the page, so we can start over. */
ret = trace_seq_to_buffer(&iter->seq,
page_address(spd.pages[i]),
iter->seq.len);
iter->seq.seq.len);
if (ret < 0) {
__free_page(spd.pages[i]);
break;
}
spd.partial[i].offset = 0;
spd.partial[i].len = iter->seq.len;
spd.partial[i].len = iter->seq.seq.len;
trace_seq_init(&iter->seq);
}
@ -5673,7 +5676,7 @@ tracing_stats_read(struct file *filp, char __user *ubuf,
cnt = ring_buffer_read_events_cpu(trace_buf->buffer, cpu);
trace_seq_printf(s, "read events: %ld\n", cnt);
count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len);
count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->seq.len);
kfree(s);
@ -6636,11 +6639,11 @@ void
trace_printk_seq(struct trace_seq *s)
{
/* Probably should print a warning here. */
if (s->len >= TRACE_MAX_PRINT)
s->len = TRACE_MAX_PRINT;
if (s->seq.len >= TRACE_MAX_PRINT)
s->seq.len = TRACE_MAX_PRINT;
/* should be zero ended, but we are paranoid. */
s->buffer[s->len] = 0;
s->buffer[s->seq.len] = 0;
printk(KERN_TRACE "%s", s->buffer);

6
kernel/trace/trace_events.c
View File

@ -1044,7 +1044,7 @@ event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
mutex_unlock(&event_mutex);
if (file)
r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->seq.len);
kfree(s);
@ -1210,7 +1210,7 @@ subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
trace_seq_init(s);
print_subsystem_event_filter(system, s);
r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->seq.len);
kfree(s);
@ -1265,7 +1265,7 @@ show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
trace_seq_init(s);
func(s);
r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->seq.len);
kfree(s);

6
kernel/trace/trace_functions_graph.c
View File

@ -1154,9 +1154,9 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
}
/* Strip ending newline */
if (s->buffer[s->len - 1] == '\n') {
s->buffer[s->len - 1] = '\0';
s->len--;
if (s->buffer[s->seq.len - 1] == '\n') {
s->buffer[s->seq.len - 1] = '\0';
s->seq.len--;
}
trace_seq_puts(s, " */\n");

174
kernel/trace/trace_seq.c
View File

@ -27,10 +27,19 @@
#include <linux/trace_seq.h>
/* How much buffer is left on the trace_seq? */
#define TRACE_SEQ_BUF_LEFT(s) ((PAGE_SIZE - 1) - (s)->len)
#define TRACE_SEQ_BUF_LEFT(s) seq_buf_buffer_left(&(s)->seq)
/* How much buffer is written? */
#define TRACE_SEQ_BUF_USED(s) min((s)->len, (unsigned int)(PAGE_SIZE - 1))
#define TRACE_SEQ_BUF_USED(s) min((s)->seq.len, (unsigned int)(PAGE_SIZE - 1))
/*
* trace_seq should work with being initialized with 0s.
*/
static inline void __trace_seq_init(struct trace_seq *s)
{
if (unlikely(!s->seq.size))
trace_seq_init(s);
}
/**
* trace_print_seq - move the contents of trace_seq into a seq_file
@ -43,10 +52,11 @@
*/
int trace_print_seq(struct seq_file *m, struct trace_seq *s)
{
unsigned int len = TRACE_SEQ_BUF_USED(s);
int ret;
ret = seq_write(m, s->buffer, len);
__trace_seq_init(s);
ret = seq_buf_print_seq(m, &s->seq);
/*
* Only reset this buffer if we successfully wrote to the
@ -72,24 +82,23 @@ int trace_print_seq(struct seq_file *m, struct trace_seq *s)
*/
void trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
{
unsigned int len = TRACE_SEQ_BUF_LEFT(s);
unsigned int save_len = s->seq.len;
va_list ap;
int ret;
if (s->full || !len)
if (s->full)
return;
__trace_seq_init(s);
va_start(ap, fmt);
ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
seq_buf_vprintf(&s->seq, fmt, ap);
va_end(ap);
/* If we can't write it all, don't bother writing anything */
if (ret >= len) {
if (unlikely(seq_buf_has_overflowed(&s->seq))) {
s->seq.len = save_len;
s->full = 1;
return;
}
s->len += ret;
}
EXPORT_SYMBOL_GPL(trace_seq_printf);
@ -104,14 +113,19 @@ EXPORT_SYMBOL_GPL(trace_seq_printf);
void trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp,
int nmaskbits)
{
unsigned int len = TRACE_SEQ_BUF_LEFT(s);
int ret;
unsigned int save_len = s->seq.len;
if (s->full || !len)
if (s->full)
return;
ret = bitmap_scnprintf(s->buffer + s->len, len, maskp, nmaskbits);
s->len += ret;
__trace_seq_init(s);
seq_buf_bitmask(&s->seq, maskp, nmaskbits);
if (unlikely(seq_buf_has_overflowed(&s->seq))) {
s->seq.len = save_len;
s->full = 1;
}
}
EXPORT_SYMBOL_GPL(trace_seq_bitmask);
@ -128,21 +142,20 @@ EXPORT_SYMBOL_GPL(trace_seq_bitmask);
*/
void trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
{
unsigned int len = TRACE_SEQ_BUF_LEFT(s);
int ret;
unsigned int save_len = s->seq.len;
if (s->full || !len)
if (s->full)
return;
ret = vsnprintf(s->buffer + s->len, len, fmt, args);
__trace_seq_init(s);
seq_buf_vprintf(&s->seq, fmt, args);
/* If we can't write it all, don't bother writing anything */
if (ret >= len) {
if (unlikely(seq_buf_has_overflowed(&s->seq))) {
s->seq.len = save_len;
s->full = 1;
return;
}
s->len += ret;
}
EXPORT_SYMBOL_GPL(trace_seq_vprintf);
@ -163,21 +176,21 @@ EXPORT_SYMBOL_GPL(trace_seq_vprintf);
*/
void trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
{
unsigned int len = TRACE_SEQ_BUF_LEFT(s);
int ret;
unsigned int save_len = s->seq.len;
if (s->full || !len)
if (s->full)
return;
ret = bstr_printf(s->buffer + s->len, len, fmt, binary);
__trace_seq_init(s);
seq_buf_bprintf(&s->seq, fmt, binary);
/* If we can't write it all, don't bother writing anything */
if (ret >= len) {
if (unlikely(seq_buf_has_overflowed(&s->seq))) {
s->seq.len = save_len;
s->full = 1;
return;
}
s->len += ret;
}
EXPORT_SYMBOL_GPL(trace_seq_bprintf);
@ -198,13 +211,14 @@ void trace_seq_puts(struct trace_seq *s, const char *str)
if (s->full)
return;
__trace_seq_init(s);
if (len > TRACE_SEQ_BUF_LEFT(s)) {
s->full = 1;
return;
}
memcpy(s->buffer + s->len, str, len);
s->len += len;
seq_buf_putmem(&s->seq, str, len);
}
EXPORT_SYMBOL_GPL(trace_seq_puts);
@ -223,12 +237,14 @@ void trace_seq_putc(struct trace_seq *s, unsigned char c)
if (s->full)
return;
__trace_seq_init(s);
if (TRACE_SEQ_BUF_LEFT(s) < 1) {
s->full = 1;
return;
}
s->buffer[s->len++] = c;
seq_buf_putc(&s->seq, c);
}
EXPORT_SYMBOL_GPL(trace_seq_putc);
@ -247,19 +263,17 @@ void trace_seq_putmem(struct trace_seq *s, const void *mem, unsigned int len)
if (s->full)
return;
__trace_seq_init(s);
if (len > TRACE_SEQ_BUF_LEFT(s)) {
s->full = 1;
return;
}
memcpy(s->buffer + s->len, mem, len);
s->len += len;
seq_buf_putmem(&s->seq, mem, len);
}
EXPORT_SYMBOL_GPL(trace_seq_putmem);
#define MAX_MEMHEX_BYTES 8U
#define HEX_CHARS (MAX_MEMHEX_BYTES*2 + 1)
/**
* trace_seq_putmem_hex - write raw memory into the buffer in ASCII hex
* @s: trace sequence descriptor
@ -273,32 +287,26 @@ EXPORT_SYMBOL_GPL(trace_seq_putmem);
void trace_seq_putmem_hex(struct trace_seq *s, const void *mem,
unsigned int len)
{
unsigned char hex[HEX_CHARS];
const unsigned char *data = mem;
unsigned int start_len;
int i, j;
unsigned int save_len = s->seq.len;
if (s->full)
return;
while (len) {
start_len = min(len, HEX_CHARS - 1);
#ifdef __BIG_ENDIAN
for (i = 0, j = 0; i < start_len; i++) {
#else
for (i = start_len-1, j = 0; i >= 0; i--) {
#endif
hex[j++] = hex_asc_hi(data[i]);
hex[j++] = hex_asc_lo(data[i]);
}
if (WARN_ON_ONCE(j == 0 || j/2 > len))
break;
__trace_seq_init(s);
/* j increments twice per loop */
len -= j / 2;
hex[j++] = ' ';
/* Each byte is represented by two chars */
if (len * 2 > TRACE_SEQ_BUF_LEFT(s)) {
s->full = 1;
return;
}
trace_seq_putmem(s, hex, j);
/* The added spaces can still cause an overflow */
seq_buf_putmem_hex(&s->seq, mem, len);
if (unlikely(seq_buf_has_overflowed(&s->seq))) {
s->seq.len = save_len;
s->full = 1;
return;
}
}
EXPORT_SYMBOL_GPL(trace_seq_putmem_hex);
@ -317,30 +325,28 @@ EXPORT_SYMBOL_GPL(trace_seq_putmem_hex);
*/
int trace_seq_path(struct trace_seq *s, const struct path *path)
{
unsigned char *p;
unsigned int save_len = s->seq.len;
int ret;
if (s->full)
return 0;
__trace_seq_init(s);
if (TRACE_SEQ_BUF_LEFT(s) < 1) {
s->full = 1;
return 0;
}
p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
if (!IS_ERR(p)) {
p = mangle_path(s->buffer + s->len, p, "\n");
if (p) {
s->len = p - s->buffer;
return 1;
}
} else {
s->buffer[s->len++] = '?';
return 1;
ret = seq_buf_path(&s->seq, path);
if (unlikely(seq_buf_has_overflowed(&s->seq))) {
s->seq.len = save_len;
s->full = 1;
return 0;
}
s->full = 1;
return 0;
return ret;
}
EXPORT_SYMBOL_GPL(trace_seq_path);
@ -366,25 +372,7 @@ EXPORT_SYMBOL_GPL(trace_seq_path);
*/
int trace_seq_to_user(struct trace_seq *s, char __user *ubuf, int cnt)
{
int len;
int ret;
if (!cnt)
return 0;
if (s->len <= s->readpos)
return -EBUSY;
len = s->len - s->readpos;
if (cnt > len)
cnt = len;
ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);
if (ret == cnt)
return -EFAULT;
cnt -= ret;
s->readpos += cnt;
return cnt;
__trace_seq_init(s);
return seq_buf_to_user(&s->seq, ubuf, cnt);
}
EXPORT_SYMBOL_GPL(trace_seq_to_user);